It is known to process food products by a system which has been called a "cook-chill" method. Such methods are directed to solving the problem of matching food production to demand and separates the food production from food serving, by creating an inventory of prepared food products. The key to safe extended storage of foods is based on very rapidly chilling the food product through the rapid bacterial growth temperature danger zone, typically between 140.degree.-45.degree. F. The quality, taste, texture and aroma of the food then is retained by refrigerated storage.
Typical cook-chill methods involve first cooking the food in an appropriate apparatus, and then immediately placing the food in a chiller whereat the temperature of the food is rapidly reduced to approximately 38.degree. F. Typically, the food is contained in plastic bags which hold individual servings or multiple-serving quantities.
Heretofore, the chiller typically has been of one or the other of two general types, namely a tumbler-type or a paddle-type. In the tumbler-type chiller, the bags of food are placed in a tank containing a chilling liquid, and the tank rotates about a non-horizontal axis to tumble the bags of food in the chilling liquid, sort of like an ordinary clothes dryer. In the paddle-type chiller, the bags of food are placed in a reservoir of chilling liquid in a tank, and paddles are used to move the liquid and food to facilitate rapid chilling of the food. Both the tumbler-type chillers and the paddle-type chillers cause problems with various types of food products, because these methods are somewhat "abusive" to the bagged food and can cause damage or break-up of food items contained in the bags. The bags may even become broken because of the abusive nature of agitating the chilling liquid. The present invention is directed to solving these problems by providing an apparatus for rapidly changing the temperature of food products by means which, in essence, do not involve any moving parts of the apparatus which could be abusive to the product.
It should be understood that, while the above background has been directed to cook-chill methods involving chilling apparatus (i.e. "chillers"), the invention is not limited to such apparatus and can be used for rapidly increasing the temperature of food products as well as reducing the temperature thereof (i.e. "rethermalizing" the food).